/**
 * 
 */
package com.hongbao.utils;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;

/**
 * @author Administrator
 * 
 */
public class WeixinSignUtil {
	// 与接口配置信息中的Token要一致

	private static String token = "weixinSK";

	/**
	 * 
	 * 验证签名
	 * 
	 * 
	 * 
	 * @param signature
	 * 
	 * @param timestamp
	 * 
	 * @param nonce
	 * 
	 * @return
	 */

	public static boolean checkSignature(String signature, String timestamp,
			String nonce) {

		String[] arr = new String[] { token, timestamp, nonce };

		// 将token、timestamp、nonce三个参数进行字典序排序

		Arrays.sort(arr);

		StringBuilder content = new StringBuilder();

		for (int i = 0; i < arr.length; i++) {

			content.append(arr[i]);

		}

		MessageDigest md = null;

		String tmpStr = null;

		try {

			md = MessageDigest.getInstance("SHA-1");

			// 将三个参数字符串拼接成一个字符串进行sha1加密

			byte[] digest = md.digest(content.toString().getBytes());

			tmpStr = byteToStr(digest);

		} catch (NoSuchAlgorithmException e) {

			e.printStackTrace();

		}

		content = null;

		// 将sha1加密后的字符串可与signature对比，标识该请求来源于微信

		return tmpStr != null ? tmpStr.equals(signature.toUpperCase()) : false;

	}

	/**
	 * 
	 * 将字节数组转换为十六进制字符串
	 * 
	 * 
	 * 
	 * @param byteArray
	 * 
	 * @return
	 */

	private static String byteToStr(byte[] byteArray) {

		String strDigest = "";

		for (int i = 0; i < byteArray.length; i++) {

			strDigest += byteToHexStr(byteArray[i]);

		}

		return strDigest;

	}

	/**
	 * 
	 * 将字节转换为十六进制字符串
	 * 
	 * 
	 * 
	 * @param mByte
	 * 
	 * @return
	 */

	private static String byteToHexStr(byte mByte) {

		char[] Digit = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A',
				'B', 'C', 'D', 'E', 'F' };

		char[] tempArr = new char[2];

		tempArr[0] = Digit[(mByte >>> 4) & 0X0F];

		tempArr[1] = Digit[mByte & 0X0F];

		String s = new String(tempArr);

		return s;

	}
	
	
	
	
}
